AI and solar energy are decades old at this point (continually improving, but they aren't new ideas). Smartphones have definitely had a huge impact on the world

AI and solar energy are decades old at this point (continually improving, but they aren't new ideas). Smartphones have definitely had a huge impact on the world but they are almost entirely a system integration problem. Biology is maybe the one field that still has a lot of novel advances coming out of it. The other thing is look at the number of people it takes to sustain those advances. There are probably 1000x more scientists and engineers in 2020 than in 1920. So even if the absolute number of technological advances is roughly constant, the productivity is way lower.